JP2006199160A - Motor control circuit for mirror device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control circuit for a mirror device capable of preventing the mirror device from stopping during its turning operation. <P>SOLUTION: In the motor control circuit for a mirror device 10, a resistor 46 and a capacitor 48 allow a transistor 64 to maintain an ON state until a timer time has elapsed. Even if an over-current flows through a motor 20 and current value of current A5 which flows through a base terminal of a transistor 54 increases to the value which allows the transistor 54 to turn on, the transistor 54 is maintained in an OFF state. In a gate terminal MOSFET 24, a constant voltage corresponding to a zenner voltage of a zenner diode 32 is kept being applied and is maintained in the ON state, and a driving current A4 is kept being provided to the motor 20. When the timer time has elapsed and the transistor 64 becomes an OFF state, the current A5 flows through an emitter-base of the transistor 54 to allow the motor 20 to be in the ON state. As a result, a gate voltage of the MOSFET 24 drops and the MOSFET becomes the OFF state and the driving current A4 is cut off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor control circuit for a mirror device used in an electric door mirror device for a vehicle.

  The so-called door mirror for rearward confirmation provided on the side of the door panel corresponding to the driver's seat and passenger seat of the vehicle can be folded and stored with the driving force of the motor until the mirror surface is substantially inward in the vehicle width direction. There is an electric door mirror device.

  Such an electric door mirror device is usually provided with a storage / deployment switch provided in the vicinity of the driver's seat of the vehicle, and the vehicle battery is connected to the storage / deployment motor via the switch and motor control circuit. The power is supplied from.

  Furthermore, in such an electric door mirror device, the control circuit is configured to stop the motor when the mirror is rotated to a predetermined deployed position and retracted position. As an example of such a control circuit, there is a configuration in which a load applied to a motor is detected, and when a load exceeding a predetermined value is applied to the motor, a current flowing through the motor is cut off (for example, Patent Documents). 1).

  In the door mirror device configured as described above, when the mirror that has been rotated to the unfolded position or the retracted position is restricted from further rotation, and the motor is in a so-called locked state, the motor has a lock current larger than the normal drive current. (Overcurrent) flows. In the above control circuit, a circuit for detecting this overcurrent is configured, and when the overcurrent flows through the control circuit, the current flowing to the motor is cut off.

By the way, this type of control circuit is configured to detect the overcurrent flowing through the motor as described above and cut off the energization to the motor. Even if it fluctuates, the power supply to the motor may be cut off. For example, when the door mirror located at the retracted position is rotated in the unfolding direction during high-speed traveling, a large wind pressure acts on the door mirror, so that the load on the motor increases and an overcurrent may temporarily flow. Even in such a case, when the control circuit detects an overcurrent, the energization to the motor is interrupted, and there is a possibility that the rotation of the mirror stops in the middle.
JP 2002-347522 A

  In consideration of the above-described facts, an object of the present invention is to provide a motor control circuit for a mirror device that can prevent a mirror from stopping during rotation.

  In order to solve the above problems, a motor control circuit for a mirror device according to a first aspect of the present invention is used in a mirror device that displaces a mirror attached to a vehicle in a predetermined direction by a driving force of a motor, and drives the motor. A motor control circuit for a mirror device that controls a drive current to be connected to the motor, and is turned on when a predetermined electrical signal is input to a specific terminal, and the drive current flows to the motor; When the input of the electrical signal is canceled, the switch unit is turned off to cut off the drive current, and is connected to the specific terminal of the switch unit, and the electrical signal is input to the specific terminal. The timer means which is turned on correspondingly and is turned off after a lapse of a predetermined time, the motor, the specific terminal of the switch means, and the timer hand When the timer means is in an on state, the electrical signal is allowed to be input to the specific terminal, and the timer means is in an off state and the current value of the drive current has risen to a predetermined value or more. In some cases, overcurrent detection means for canceling the input of the electrical signal to the specific terminal is provided.

  In the motor control circuit for a mirror device according to claim 1, when a predetermined electric signal is inputted to a specific terminal of the switch means connected to the motor, the switch means is turned on and the timer means is turned on. . When the timer means is in the on state, the electric current is allowed to be input to the specific terminal of the switch means by the overcurrent detection means, so that the switch means continues to be kept in the on state, whereby the drive current is supplied to the motor The motor rotates forward or reverse in accordance with the direction of the drive current. Therefore, for example, if this motor is a motor for storing and unfolding the mirror, the mirror is displaced from the retracted position to the unfolded position or from the unfolded position to the retracted position according to the rotation direction of the motor.

  If the displacement of the mirror that has reached the retracted position or the unfolded position is limited by, for example, a stopper or the like, the current value of the drive current flowing through the motor rises to a predetermined value or more (although an overcurrent flows through the motor). The overcurrent detection means allows the electric signal to be input to a specific terminal of the switch means until the timer means is turned off. For this reason, the drive current continues to be supplied to the motor. Then, when a predetermined time set in the timer means elapses, the input of the electric signal to the specific terminal of the switch means is canceled by the overcurrent detection means, the switch means is turned off, and the drive current is cut off. The

  That is, in this mirror device motor control circuit, the supply of drive current is maintained even if an overcurrent flows through the motor until a predetermined time (timer time) set in the timer means elapses (overcurrent). Since the detection means does not function), for example, even if the load on the motor temporarily rises during the rotation of the mirror and an overcurrent flows through the motor, the mirror does not stop unnecessarily.

  Thus, in the mirror device motor control circuit according to the first aspect, it is possible to prevent the mirror from stopping during the rotation.

  A mirror device motor control circuit according to a second aspect of the present invention is the mirror device motor control circuit according to the first aspect, wherein the timer means is connected to the specific terminal of the switch means, and A first switch element that is turned on in response to an input of the electrical signal; and a first switch element that is connected to the first switch element and that has passed the predetermined time after the first switch element is turned on. And a time constant circuit for turning off one switch element.

  In the motor control circuit for a mirror device according to the second aspect, when a predetermined electrical signal is input to the specific terminal of the switch means, the first switch element is turned on. A time constant circuit is connected to the first switch element, and the first switch element is turned off by the time constant circuit after a lapse of a predetermined time from being turned on.

  Thus, in the motor control circuit for a mirror device according to claim 2, the timer means can be configured simply.

  A mirror device motor control circuit according to a third aspect of the present invention is the mirror device motor control circuit according to the first or second aspect, wherein the overcurrent detection means is connected to the specific terminal of the switch means. In the OFF state, the input of the electrical signal to the specific terminal is allowed, and when the predetermined operation signal is input, it is turned ON and the input of the electrical signal to the specific terminal is canceled. A second switch element that is connected to the motor and the second switch element, and an operation for inputting the predetermined operation signal to the second switch element when a current value of the drive current rises to a predetermined value or more. The signal input circuit is connected to the timer means, the second switch element, and the operation signal input circuit. When the timer means is in an on state, it is in an on state and the operation signal input circuit is turned on. The operation signal input to the second switch element is released, and when the timer means is in an OFF state, the operation signal input circuit inputs the operation signal to the second switch element. And a third switch element to be allowed.

  In the motor control circuit for a mirror device according to claim 3, when a predetermined electrical signal is inputted to a specific terminal of the switch means and the timer means is turned on, the third switch element connected to the timer means is turned on. Become. In this state, since the operation signal input to the second switch element by the operation signal input circuit is canceled, even if the current value of the drive current flowing through the motor rises above a predetermined value, the second switch element is turned off. Maintain state. As a result, the input of an electrical signal to a specific terminal of the switch means is allowed, so that the switch means is kept on, a drive current flows through the motor, and the motor is driven.

  When a predetermined time set in the timer means elapses and the timer means is turned off, the third switch element is turned off. In this state, when the current value of the drive current flowing through the motor rises to a predetermined value or more, the operation signal is input to the second switch element by the operation signal input circuit. For this reason, a 2nd switch element will be in an ON state, and the input of the electric signal to the specific terminal of a switch means will be cancelled | released. As a result, the switch means is turned off to cut off the drive current to the motor.

  Thus, in the motor control circuit for a mirror device according to the third aspect, the overcurrent detection means can be configured simply.

  As described above, according to the motor control circuit for a mirror device of the present invention, it is possible to prevent the mirror from stopping during the rotation.

[First Embodiment]
FIG. 1 is a circuit diagram showing a configuration of a mirror device motor control circuit 10 (hereinafter simply referred to as “control circuit 10”) according to a first embodiment of the present invention.

  As shown in the figure, the control circuit 10 includes a switch unit 12 and a drive control unit 14. The switch unit 12 includes a pair of switches 16 and 18. The switch 16 includes three terminals 16A, 16B, and 16C. Either one of the terminal 16A and the terminal 16B or between the terminal 16B and the terminal 16C is in a conductive state, and the other is in a disconnected state. Can be done.

  On the other hand, the switch 18 is similarly provided with three terminals 18A, 18B, and 18C, and either one of the terminals 18A and 18B and between the terminals 18B and 18C is in a conducting state, and the other is disconnected. It can be in a state. However, the terminal 16A of the switch 16 is connected to the positive terminal of the battery mounted on the vehicle, whereas the terminal 18A of the switch 18 is grounded. The switches 16 and 18 are connected to a terminal 16A and a terminal 18C, and to a terminal 16C and a terminal 18A.

  Further, these switches 16 and 18 are set so as to be linked to each other. When the terminal 16A and the terminal 16B are connected by the switch 16, the terminal 18A and the terminal 18B are connected by the switch 18, and the switch 16 is connected. When the terminal 16B and the terminal 16C are connected, the switch 18 connects the terminal 18B and the terminal 18C.

  On the other hand, the drive control unit 14 includes a pair of n-channel field effect transistors 22 and 24 (hereinafter simply referred to as “MOSFETs 22 and 24”) as switch means. The MOSFET 22 has a drain terminal connected to one terminal of the motor 20 and a source terminal connected to one terminal of an overcurrent detection resistor 26 constituting an overcurrent detection means. The other terminal of the overcurrent detection resistor 26 is connected to the terminal 16B of the switch 16.

  On the other hand, the MOSFET 24 has a drain terminal connected to the other terminal of the motor 20 and a source terminal connected to one terminal of the overcurrent detection resistor 28 constituting the overcurrent detection means. The other terminal of the overcurrent detection resistor 28 is connected to the terminal 18B of the switch 18.

  The motor 20 described above is housed inside a door mirror 26 as a mirror shown in FIG. 2, and an output shaft is provided so that the door mirror 26 can be rotated about this axis with the vehicle vertical direction being an axial direction. It is directly or indirectly mechanically connected to the supporting shaft 27 to be supported. Then, when the output shaft of the motor 20 rotates in the forward direction (forward rotation), the door mirror 26 rotates in the unfolding direction (arrow Y1 direction in FIG. 4), and the output shaft of the motor 20 rotates in the reverse direction (reverse rotation). As a result, the door mirror 26 is rotated in the retracted direction (the direction of the arrow Y2 in FIG. 4).

  The drive control unit 14 includes a pair of Zener diodes 30 and 32 and a resistor 34. The Zener diode 30 has an anode terminal connected to the terminal 16B of the switch 16 and the other terminal of the overcurrent detection resistor 26, and a cathode terminal serving as a specific terminal of the MOSFET 22 and one terminal of the resistor 34. It is connected to the. On the other hand, the Zener diode 32 has an anode terminal connected to the terminal 18B of the switch 18 and the other terminal of the overcurrent detection resistor 28, and a cathode terminal serving as a specific terminal of the MOSFET 24 and the resistor 34. Is connected to the other terminal.

  Further, the drive control unit 14 includes a pair of PNP transistors 36 and 38 as a first switch element constituting a timer means. The transistor 36 has an emitter terminal connected to the cathode terminal of the Zener diode 30 and the gate terminal of the MOSFET 22, and a base terminal connected to one terminal of the resistor 40 constituting the time constant circuit of the timer means. The other terminal of the resistor 40 is connected to one terminal of a capacitor 42 that forms a time constant circuit together with the resistor 40, and the anode terminal of the diode 44. The other terminal of the capacitor 42 is connected to the terminal 16B of the switch 16 and the other terminal of the overcurrent detection resistor 26, and the cathode terminal of the diode 44 is connected to the gate terminal of the MOSFET 22 and the cathode terminal of the Zener diode 30. Has been.

  On the other hand, the transistor 38 has an emitter terminal connected to the cathode terminal of the Zener diode 32 and the gate terminal of the MOSFET 24, and a base terminal connected to one terminal of the resistor 46 constituting the time constant circuit of the timer means. The other terminal of the resistor 46 is connected to one terminal of a capacitor 48 that forms a time constant circuit together with the resistor 46, and the anode terminal of the diode 50. The other terminal of the capacitor 48 is connected to the terminal 18B of the switch 18 and the other terminal of the overcurrent detection resistor 28. The cathode terminal of the diode 50 is connected to the gate terminal of the MOSFET 24 and the cathode terminal of the Zener diode 32. Has been.

  In addition, the drive control unit 14 includes a pair of NPN transistors 52 and 54 as a second switch element that constitutes an overcurrent detection unit. The transistor 52 has an emitter terminal connected to the terminal 16B of the switch 16 and the other terminal of the overcurrent detection resistor 26, and a collector terminal connected to the cathode terminal of the Zener diode 30 and the gate terminal of the MOSFET 22. The base terminal of the transistor 52 is connected to one terminal of the resistor 56 constituting the operation signal input circuit and the collector terminal of an NPN transistor 58 as a third switch element. The other terminal of the resistor 56 is connected to the one terminal of the motor 20. The transistor 58 has an emitter terminal connected to the terminal 16B of the switch 16 and a base terminal connected to the collector terminal of the transistor 36 via the resistor 60.

  On the other hand, the transistor 54 has an emitter terminal connected to the terminal 18B of the switch 18 and the other terminal of the overcurrent detection resistor 28, and a collector terminal connected to the cathode terminal of the Zener diode 32 and the gate terminal of the MOSFET 24. Yes. The base terminal of the transistor 54 is connected to one terminal of the resistor 62 constituting the operation signal input circuit and the collector terminal of an NPN transistor 64 as a third switch element. The other terminal of the resistor 62 is connected to the other terminal of the motor 20. The transistor 64 has an emitter terminal connected to the terminal 18B of the switch 18 and a base terminal connected to the collector terminal of the transistor 38 via the resistor 66.

  Next, the operation of the first embodiment will be described.

  The control circuit 10 having the above configuration normally operates as in a timing chart shown in FIG. That is, as shown in FIG. 1, when the terminal 16A and the terminal 16B of the switch 16 are connected, and when the terminal 18A and the terminal 18B of the switch 18 are connected, the terminal 16B of the switch 16 → the Zener diode 30 → the resistor 34 → A current A1 flows through the path from the Zener diode 32 to the terminal 18B of the switch 18, and a constant voltage corresponding to the Zener voltage of the Zener diode 32 is applied to the timer circuit (the transistor 38, the resistor 46, and the capacitor 48). Due to this constant voltage, a current A 2 flows through the path between the emitter and base of the transistor 38 → the resistor 46 → the capacitor 48. Until a predetermined amount of charge is accumulated in the capacitor 48, a current A2 of a predetermined value or more flows between the emitter and base of the transistor 38, and the transistor 38 is turned on.

  When the transistor 38 is turned on, a current A3 flows through a path between the emitter and collector of the transistor 38 → the resistor 66 → the emitter / base of the transistor 64, and the transistor 64 is turned on. When the transistor 64 is turned on in this way, the base terminal of the transistor 54 is grounded via the emitter terminal and the collector terminal of the transistor 64. That is, until a predetermined amount of charge is accumulated in the capacitor 48 and the transistor 38 and the transistor 64 are turned off (until the timer time T1 determined by the time constant of the resistor 46 and the capacitor 48 elapses), the transistor 54 Keep off.

  At this time, a constant voltage corresponding to the Zener voltage of the Zener diode 32 is applied to the gate terminal of the MOSFET 24 (a predetermined electric signal is input). As a result, the MOSFET 24 is turned on.

  When the MOSFET 24 is turned on, the motor 20 is driven along the path of the terminal 16B of the switch 16 → the overcurrent detection resistor 26 → the parasitic diode 22A of the MOSFET 22 → the motor 20 → the MOSFET 24 → the overcurrent detection resistor 28 → the terminal 18B of the switch 18. Drive current A4 starts to flow. Thereby, the output shaft of the motor 20 rotates forward, and the door mirror 26 is rotated in the unfolding direction (the direction of the arrow Y1 in FIG. 2) by the driving force of the motor 20.

  By the way, as shown in the time chart of FIG. 3, immediately after the terminals 16A and 16B of the switch 16 and the terminals 18A and 18B of the switch 18 are connected at the point P1, it is larger than the normal driving current A4. Since the pulsed inrush current flows to the motor 20, the current value of the drive current A4 rapidly increases and reaches the point P2 (current detection level Id). For this reason, the voltage across the overcurrent detection resistor 28 connected in series to the motor 20 rises above a predetermined value. At this time, the current value of the current A5 (operation signal) flowing to the base terminal of the transistor 54 via the resistor 62 also rises to a value that can turn on the transistor 54, but until the timer time T1 elapses as described above. Since the on state of the transistor 64 is maintained, the current A5 flows to the terminal 18B of the switch 18 through the emitter and collector of the transistor 64, and the transistor 54 maintains the off state. Therefore, until the timer time T1 elapses, a constant voltage corresponding to the Zener voltage of the Zener diode 32 is continuously applied to the gate terminal of the MOSFET 24. As a result, the MOSFET 24 is kept on, and the output shaft of the motor 20 Keeps going forward.

  When the output shaft of the motor 20 continues to rotate normally, when the door mirror 26 reaches the deployed position, the rotation of the door mirror 26 is restricted by a stopper member and a vehicle body (not shown). When the rotation of the door mirror 26 is restricted, the output shaft of the motor 20 does not rotate despite the drive current A4 flowing through the motor 20, so that the drive current flowing through the motor 20 as shown in FIG. The current value of A4 increases rapidly (overcurrent flows through the motor 20) and reaches the point P4 (current detection level Id). For this reason, the voltage across the overcurrent detection resistor 28 connected in series to the motor 20 rises above a predetermined value. At this time, the current value of the current A5 (operation signal) flowing to the base terminal of the transistor 54 via the resistor 62 also rises to a value that can turn on the transistor 54, but until the timer time T1 elapses as described above. Since the on state of the transistor 64 is maintained, the current A5 flows to the terminal 18B of the switch 18 through the emitter and collector of the transistor 64, and the transistor 54 maintains the off state. Therefore, a constant voltage corresponding to the Zener voltage of the Zener diode 32 is continuously applied to the gate terminal of the MOSFET 24, whereby the MOSFET 24 is kept on.

  When the timer time T1 elapses, the transistor 38 and the transistor 64 are turned off, whereby a current A5 of a predetermined value or more flows between the emitter and base of the transistor 54, and the transistor 54 is turned on. For this reason, the potential of the gate terminal of the MOSFET 24 is lowered, the MOSFET 24 is turned off, and the drive current A4 to the motor 20 is cut off.

  Thus, in the present control circuit 10, until the timer time T1 elapses, the supply of the drive current A4 is maintained even if an overcurrent flows through the motor 20 (a configuration in which the overcurrent detection means does not function). . Therefore, even when an overcurrent is temporarily detected due to the inrush current to the motor 20 as described above, the supply of the drive current A4 to the motor 20 is not interrupted, and the door mirror 26 is reliably moved to the predetermined deployment position. Can be rotated.

  On the other hand, when a predetermined drag force is applied to the rotation of the door mirror 26 (for example, a large wind pressure acts on the door mirror 26 by displacing the door mirror 26 located at the retracted position in the retracted direction by the driving force of the motor 20 during high-speed traveling). The rotation time T2 of the motor 20 is longer than the preset timer time T1 in the case where the viscosity of the grease applied to the rotating mechanism of the door mirror 26 increases due to a decrease in temperature). There is a possibility.

  In such a case, the control circuit 10 operates as in the timing chart shown in FIG. That is, when the timer time T1 elapses, the transistor 38 and the transistor 64 are turned off, but the transistor 54 is kept off until an overcurrent flows in the motor 20, so that the MOSFET 24 is also kept on, and the motor 20 The output shaft continues to rotate forward. Thereby, the door mirror 26 is rotated to a predetermined deployment position, and the rotation of the door mirror 26 is limited by a stopper member and a vehicle body (not shown). When the rotation of the door mirror 26 is restricted, the output shaft of the motor 20 does not rotate despite the drive current A4 flowing through the motor 20, so that the drive current flowing through the motor 20 as shown in FIG. The current value of A4 increases rapidly (overcurrent flows through the motor 20) and reaches the point P4 (current detection level Id). Therefore, the voltage across the overcurrent detection resistor 28 connected in series with the motor 20 rises to a predetermined value or more, and the current value of the current A5 (actuation signal) flowing to the base terminal of the transistor 54 via the resistor 62. Also rises to a value that allows the transistor 54 to be turned on. In this case, since the transistor 64 is off as described above, the current A5 immediately flows between the emitter and base of the transistor 54, and the transistor 54 is turned on. As a result, the potential of the gate terminal of the MOSFET 24 is lowered, the MOSFET 24 is turned off, and the drive current A4 to the motor 20 is interrupted.

  As described above, in the present control circuit 10, even when the rotation time T2 of the motor 20 is longer than the preset timer time T1, the door mirror 26 during the rotation does not stop unnecessarily.

  As shown in FIG. 1, in the present control circuit 10, the switch 16 side (upper half with respect to the motor 20 in FIG. 1) and the switch 18 side (with the motor 20 in FIG. The circuit configuration is symmetrical with the lower half). Therefore, the same effect can be obtained when the terminal 16B and the terminal 16C of the switch 16 are connected and the terminal 18B and the terminal 18C of the switch 18 are connected (when the door mirror 26 is displaced from the deployed position to the retracted position).

  Further, by switching the switches 16 and 18 as described above, the electric charge stored in the capacitors 42 and 48 is released through the diodes 44 and 50. Therefore, when the switches 16 and 18 are switched again, the capacitor 42 48, the time constant determined by the capacitor 42 and the resistor 40 and the time constant determined by the capacitor 48 and the resistor 46 can be guaranteed.

  As described above, in the control circuit 10 according to the first embodiment of the present invention, it is possible to prevent the door mirror 26 from stopping during the rotation.

  In addition, in the control circuit 10 according to the first embodiment of the present invention, the timer circuit including the transistor 36, the resistor 40, and the capacitor 42 always operates under a constant voltage by the Zener diode 30, and the transistor 38 , The resistor 46 and the capacitor 48 always operate under a constant voltage by the Zener diode 32. Therefore, a stable timer time can be obtained even when the power supply voltage (the voltage of the vehicle battery) fluctuates. In addition, the Zener diodes 30 and 32 stabilize the voltage applied to the gate terminals of the MOSFETs 22 and 24 to a constant voltage, so that the MOSFETs 22 and 24 can be protected from a surge or the like.

  Next, another embodiment of the present invention will be described.

Note that components that are basically the same as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.
[Second Embodiment]
FIG. 5 is a circuit diagram showing the configuration of a mirror device motor control circuit 70 (hereinafter simply referred to as “control circuit 70”) according to the second embodiment of the present invention.

  The control circuit 70 has basically the same configuration as the control circuit 10 according to the first embodiment, and includes a switch unit 12 and a drive control unit 72.

  The switch unit 12 has the same configuration as the switch unit 12 according to the first embodiment.

  The drive control unit 72 has basically the same configuration as the drive control unit 14 according to the first embodiment, but includes a pair of resistors 74 and 76. The resistor 74 has one terminal connected to the gate terminal of the MOSFET 22 and the other terminal connected to the base terminal of the transistor 36 and the one terminal of the resistor 40. The resistor 76 has one terminal connected to the gate terminal of the MOSFET 24, and the other terminal connected to the base terminal of the transistor 38 and the one terminal of the resistor 46.

  The control circuit 70 having the above configuration also has basically the same effects as the control circuit 10 according to the first embodiment.

In addition, since the resistors 74 and 76 are added to the control circuit 70, the gate voltages of the MOSFETs 22 and 24 rapidly decrease when the transistors 52 and 54 are turned on. That is, since the MOSFETs 22 and 24 pass through the active state in a short time, the MOSFETs 22 and 24 can be prevented from being heated.
[Third Embodiment]
FIG. 6 is a circuit diagram showing the configuration of a mirror device motor control circuit 80 (hereinafter simply referred to as “control circuit 80”) according to the third embodiment.

  The control circuit 80 has basically the same configuration as the control circuit 70 according to the second embodiment, and the drive control unit 82 includes a pair of resistors 84 and 86. However, the resistor 84 has one terminal connected to the gate terminal of the MOSFET 22, and the other terminal connected to the other terminal of the resistor 40, the one terminal of the capacitor 42, and the anode terminal of the diode 44. Yes. The resistor 86 has one terminal connected to the gate terminal of the MOSFET 24, and the other terminal connected to the other terminal of the resistor 46, the one terminal of the capacitor 48, and the anode terminal of the diode 50. Yes.

  The control circuit 80 configured as described above has basically the same operational effects as the control circuit 70 according to the second embodiment.

It is a circuit diagram which shows the structure of the motor control circuit for mirror apparatuses which concerns on the 1st Embodiment of this invention. It is the perspective view which fractured | ruptured a part of door mirror comprised by applying the motor control circuit for mirror apparatuses which concerns on the 1st Embodiment of this invention. In the motor control circuit for a mirror device according to the first embodiment of the present invention, a change in the current value of the drive current when the timer time is longer than the motor rotation time, and the first switch element and the second switch It is a time chart which shows the ON / OFF state of an element, a 3rd switch element, and a switch means. In the motor control circuit for a mirror device according to the first embodiment of the present invention, the change in the current value of the drive current when the motor rotation time is longer than the timer time, and the first switch element and the second switch It is a time chart which shows the ON / OFF state of an element, a 3rd switch element, and a switch means. It is a circuit diagram which shows the structure of the motor control circuit for mirror apparatuses which concerns on the 2nd Embodiment of this invention. It is a circuit diagram which shows the structure of the motor control circuit for mirror apparatuses which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

10 Mirror device motor control circuit
20 Motor
22 Field effect transistor (switch means)
24 Electrolytic effect transistor (switch means)
36 transistor (first switch element)
38 transistor (first switch element)
40 Resistance (time constant circuit)
42 Capacitor (Time constant circuit)
46 Resistance (Time constant circuit)
48 capacitors (time constant circuit)
52 transistor (second switch element)
54 transistor (second switch element)
56 Resistance (actuation signal input circuit)
58 transistor (third switch element)
62 Resistance (actuation signal input circuit)
64 transistors (third switch element)
70 Motor control circuit for mirror device
80 Motor control circuit for mirror device

Claims (3)

A mirror device motor control circuit for controlling a drive current for driving a motor used in a mirror device for displacing a mirror attached to a vehicle in a predetermined direction by a driving force of a motor,
Connected to the motor and turned on when a predetermined electrical signal is input to a specific terminal, and flows the drive current to the motor, and is turned off by releasing the input of the electrical signal. Switch means for cutting off the current;
Timer means connected to the specific terminal of the switch means, and turned on in response to the electrical signal being input to the specific terminal, and turned off after a predetermined time,
Connected to the motor, the specific terminal of the switch means, and the timer means. When the timer means is in an ON state, the electric signal is allowed to be input to the specific terminal, and the timer means is turned off. Overcurrent detection means for canceling the input of the electrical signal to the specific terminal when the current value of the drive current rises above a predetermined value in a state;
A motor control circuit for a mirror device comprising: The timer means includes
A first switch element connected to the specific terminal of the switch means and turned on in response to the electrical signal being input to the specific terminal;
A time constant circuit which is connected to the first switch element and which turns off the first switch element after a lapse of the predetermined time after the first switch element is turned on;
The motor control circuit for a mirror device according to claim 1, comprising: The overcurrent detection means includes
It is connected to the specific terminal of the switch means, and when it is in an off state, the electric signal is allowed to be input to the specific terminal and is turned on when a predetermined operation signal is input. A second switch element for canceling the input of the electrical signal to the terminal;
An operation signal input circuit connected to the motor and the second switch element, and configured to input the predetermined operation signal to the second switch element when a current value of the drive current rises to a predetermined value or more;
It is connected to the timer means, the second switch element, and the operation signal input circuit, and is turned on when the timer means is in an on state, and the operation signal to the second switch element by the operation signal input circuit is A third switch element that releases the input and is turned off when the timer means is in an off state, and allows the operation signal input circuit to input the operation signal to the second switch element;
3. The motor control circuit for a mirror device according to claim 1, further comprising:

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